九龙江河口上游表层沉积物中重金属赋存形态及生态风险  

Speciation and potential ecological risk of heavy metals in the surface sediments from upstream of Jiulong river estuary

作　　者：于瑞莲[1] 余伟河[1] 胡恭任[1] 何海星[1] 林承奇[1] 

机构地区：[1]华侨大学化工学院,厦门361021

出　　处：《环境化学》2013年第12期2321-2328,共8页Environmental Chemistry

基　　金：国家自然科学基金项目(21077036);福建省自然科学基金项目(2011J01273);华侨大学2012年福建省大学生创新创业训练计划项目(16)资助

摘　　要：分析了九龙江河口上游表层沉积物中9种重金属元素(Zn、Ni、Fe、Mn、Pb、Cu、Cr、Cd、Hg)的含量,结果显示,Cd、Hg、Pb、Zn、Cu、Ni在所有采样点的含量均超过中国浅海沉积物背景值,表明研究区沉积物中上述元素已有不同程度的富集.采用改进的BCR四步连续提取法对沉积物中Zn、Ni、Fe、Mn、Pb、Cu、Cr进行形态分析,结果表明,Mn主要以弱酸溶态存在,Pb主要以可还原态存在,其余元素主要以残渣态存在;各元素可提取态占总量的比例顺序为Mn(81.3%)>Pb(64.9%)>Zn(49.5%)>Cu(48.4%)>Cr(47.7%)>Ni(33.5%)>Fe(26.5%).潜在生态危害指数表明,研究区沉积物已受到多种重金属的严重综合污染;Cd潜在生态危害程度极强,Hg潜在生态危害程度很强,其余元素潜在生态危害程度轻微;从多元素生态风险指数来看,九龙江河口上游表层沉积物中重金属元素的综合潜在生态风险程度极强.Concentrations of nine sediments collected from the heavy metals （Zn, Ni, Fe, Mn, Pb, Cu, Cr, Cd and Hg） in the surface upstream of Jiulong river estuary were determined. The results showed that the concentrations of Cd, Hg, Pb, Zn, Cu and Ni at all the sampling sites were higher than the background values of China coastal sediments, indicating that the above heavy metals were enriched to some extent in the sediments. A modified BCR four-step sequential extraction procedure was used to obtain the speciation of Zn, Ni, Fe, Mn, Pb, Cu and Cr in the sediments. The results showed that Mn mainly existed in the acid extractable fraction, Pb mainly existed in the reducible fraction, while the other elements were mainly present in the residual fraction. The average ratios of extractable content to total content of the nine elements was in theorderofMn（81.3%） 〉Pb（64.9%） 〉Zn（49.5%） 〉Cu（48.4%） 〉Cr（47.7%） 〉Ni（33.5%） 〉 Fe （26.5 % ）. The results of potential ecological risk indices of heavy metals indicated that the comprehensive contamination of the heavy metals in the studied sediments was considerably serious. Cd showed extremely high potential ecological risk, Hg showed very high potential ecological risk, while the other elements presented low potential ecological risk in the sediments. The comprehensive potential ecological risk of the nine heavy metals in the sediments was extremely high.

关 键 词：九龙江河口上游 表层沉积物 重金属 赋存形态 生态风险 

分 类 号：X832[环境科学与工程—环境工程] X820.4